Credit card fraud is a significant problem for credit card companies, the merchants that accept such cards, and legitimate card holders. For example, physical cards are often stolen or misplaced, and then used by someone other than the cardholder in a physical retail establishment. In some cases, a signature on a receipt or on an electronic pad is required, which may then be compared to the cardholder's signature on the card. In addition, the merchant may ask for additional identification, such as a driver's license, in order to verify that the cardholder is the one making the purchase. However, often these steps are not performed. The growth of online banking and retail services has also lead to a growing problem of fraudulent transactions involving such services.